Let's tackle the lights first. During any on-track session, a green light means the track is live, clear and safe to continue. The lights changing to red means there is an incident or debris on track and all cars must return at a reduced speed to the pits.
The start of the race, once all drivers are lined up in their correct grid positions, takes place after a sequence of five red lights illuminate one at a time at one-second intervals, with the five lights being extinguished after a preset delay of between 0.2 to three seconds to signify the start of the race. Why the variance between 0.2 and three seconds? To stop drivers attempting to 'time' their starts for safety reasons by anticipating when the lights are going to go out.
If a start is delayed for any reason, the five lights above the starting grid will flash yellow, and the drivers will complete an extra formation lap to reset the grid, with one lap removed from the distance of the race.
As for the flags waved by the trackside marshals (which are reflected in the LED digital panels you see around the circuit), there's seven you need to commit to memory.
- Yellow: A single yellow flag means overtaking is prohibited because of danger near the track; double waved yellow flags means drivers must slow down and be prepared to stop.
- Red: Halts the race/session and sees cars return to pit lane because of bad weather, debris on track or other danger that can't be cleared under a yellow flag.
- Blue: Indicated to a driver that a slower car is about to be overtaken by a faster one, typically used when a driver is being lapped.
- Green: Racing has started/been resumed after a yellow flag period.
- Black: Indicates a driver has been disqualified from the race and must return to the pits immediately.
- White: Indicates there is a slow-moving vehicle on track (the safety car, a course car, a recovery vehicle).
- Chequered: signifies the end of an on-track session – and the one every driver wants to see first on Sunday afternoon at Albert Park.